Similarity analysis method, apparatus, and system

ABSTRACT

Embodiments of the present invention provide a similarity analysis method, an apparatus, and a system. The method includes: acquiring file fingerprint information of a file to be analyzed; sending an analysis request that carries the file fingerprint information to at least two MDSs; selecting at least one group according to an analysis result returned by each MDS, where the analysis result includes a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information and is found by the MDS; and the MDS locally queries a duplicate data block in the selected group. In this way, each MDS needs to query only a file fingerprint information set of a group that the MDS itself is responsible for, which reduces the amount of data retrieval and waiting time of reading, writing, and locking a database file.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Chinese Patent Application No. 201210494714.3, filed on Nov. 28, 2012, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

Embodiments of the present invention relate to the field of data storage, and in particular to a similarity analysis method, an apparatus, and a system.

BACKGROUND

With development of technologies, the amount of information in the society increases sharply, and an increase in the amount of data that needs to be stored and consequent increases in storage capacity and storage costs have become an important problem that an enterprise needs to consider. A data de-duplication technology effectively reduces required storage capacity in scenarios such as a data backup scenario and reduces storage costs by storing only a unique instance for the same data appearing many times in stored data. In the data de-duplication technology, using multi-node concurrent data de-duplication to accelerate a processing rate of data de-duplication and improve performance of the data de-duplication has been proved to be an effective method.

In the multi-node data de-duplication solution, when querying a duplicate data block, each block needs to query all block records to confirm whether duplicate data exists. Therefore, the querying takes a long time when there is a large amount of data de-duplication. To improve the performance of data de-duplication, each block of a file with a relatively high similarity is compared with each block in a group that has a relatively high similarity with the file, so as to perform data de-duplication in a group. In this way, only a block record in the group needs to be queried when a duplicate data block is queried, and the objective of improving the performance of the data de-duplication is achieved by compromising a limited de-duplication rate.

Although the multi-node data de-duplication based on group reduces data querying time, when a similarity analysis is performed on a file to determine a group, a fingerprint of each file needs to be queried and matched with fingerprints of all groups because a fingerprint of a file and fingerprints of all groups need to be queried and matched to determine a similarity. In addition, for the purpose of ensuring querying accuracy, when a similarity analysis is performed on each file, a file that saves a group fingerprint needs to be locked. As a result, multiple nodes cannot concurrently perform the matching querying, which is a performance bottleneck of multi-node data de-duplication of a group.

SUMMARY

Embodiments of the present invention provide a similarity analysis method, an apparatus, and a system, which are used to solve a problem that existing similarity analysis becomes a performance bottleneck of multi-node data de-duplication of a group.

According to a first aspect, an embodiment of the present invention provides a similarity analysis method, including:

acquiring file fingerprint information of a file to be analyzed;

sending an analysis request that carries the file fingerprint information to at least two servers (MDSs) meta data servers (MDSs), so that the at least two MDSs query their respective local file fingerprint information sets according to the file fingerprint information, where each file fingerprint information set includes file fingerprint information in each group that the MDSs are responsible for;

selecting at least one group according to an analysis result returned by each MDS, where the analysis result includes a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information and is found by each MDS according to each local file fingerprint information set; and

sending block fingerprint information, acquired in advance, of each data block in the file to be analyzed to an MDS that the selected group belongs to, so that the MDS compares the block fingerprint information of each data block in the file to be analyzed with a local block fingerprint information base in the selected group, so as to query a duplicate data block, where the block fingerprint information base in the selected group includes block fingerprint information.

In a first possible implementation manner of the first aspect, the selecting at least one group according to an analysis result returned by each MDS includes:

if at least one highest similarity in the analysis result returned by each MDS is higher than a preset threshold, selecting at least one group corresponding to the at least one highest similarity; and

if no similarity in the analysis result returned by each MDS is higher than the preset threshold, selecting at least one pre-established idle group.

In combination with the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the analysis result further includes load information of each MDS; and

the selecting at least one pre-established idle group includes:

selecting at least one idle group that belongs to an MDS with a minimum load.

In combination with the first aspect or several possible implementation manners of the first aspect, in a third possible implementation manner of the first aspect, before the acquiring file fingerprint information of a file to be analyzed, the method further includes:

establishing a preset number of idle groups; and

allocating the preset number of idle groups to the multiple MDSs according to a preset allocation policy.

According to a second aspect, an embodiment of the present invention provides a similarity analysis method, including:

receiving an analysis request sent by a data de-duplicate engine DDE, where the analysis request carries file fingerprint information of a file to be analyzed;

querying each local file fingerprint information set, where each file fingerprint information set includes file fingerprint information in each group that an MDS is responsible for, and acquiring a similarity between the file fingerprint information in the analysis request and each group that the MDS is responsible for; and

sending an analysis result to the DDE, where the analysis result includes a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information.

In a first possible implementation manner of the second aspect, the querying each local file fingerprint information set and acquiring a similarity between the file fingerprint information in the analysis request and each group that the MDS is responsible for include:

acquiring a similarity between file fingerprint information of each file in each group and the file fingerprint information in the analysis request; and

using, based on each group, the highest similarity among similarities between file fingerprint information of each file in a group and the file fingerprint information in the analysis request as a similarity between the group and the file fingerprint information in the analysis request, so as to obtain the similarity between each group and the file fingerprint information in the analysis request.

In combination with the second aspect or the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, after sending an analysis result to the DDE, the method further includes:

receiving a querying request of the DDE, where the querying request includes block fingerprint information of each data block in the file to be analyzed and a group number of a group selected by the DDE;

comparing the block fingerprint information of each data block with a block fingerprint information base in the selected group, so as to query a duplicate data block, where the block fingerprint information base in the selected group includes block fingerprint information;

saving block fingerprint information of a non-duplicate data block among each data block to the block fingerprint information base in the selected group; and

saving the file fingerprint information of the file to be analyzed to a file fingerprint information set in the selected group.

According to a third aspect, an embodiment of the present invention provides a data de-duplicate engine DDE, including:

an acquiring module, configured to acquire file fingerprint information of a file to be analyzed;

a sending module, configured to send an analysis request that carries the file fingerprint information to at least two servers (MDSs) meta data servers (MDSs), so that the at least two MDSs query their respective local file fingerprint information sets according to the file fingerprint information, where each file fingerprint information set includes file fingerprint information in each group that the MDSs are responsible for;

a selecting module, configured to select at least one group according to an analysis result returned by each MDS, where the analysis result includes a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information and is found by each MDS according to each local file fingerprint information set; and

an allocation module, configured to send block fingerprint information, acquired in advance, of each data block in the file to be analyzed to an MDS that the selected group belongs to, so that the MDS compares the block fingerprint information of each data block in the file to be analyzed with a local block fingerprint information base in the selected group, so as to query a duplicate data block, where the block fingerprint information base in the selected group includes block fingerprint information.

In a first possible implementation manner of the third aspect, the selecting module is specifically configured to:

if at least one highest similarity in the analysis result returned by each MDS is higher than a preset threshold, select at least one group corresponding to the at least one highest similarity; and

if no similarity in the analysis result returned by each MDS is higher than the preset threshold, select at least one pre-established idle group.

In combination with the first possible implementation manner of the third aspect, in a second possible implementation manner of the third aspect, the analysis result further includes load information of each MDS; and

in the condition that no similarity in the analysis result returned by each MDS is higher than the preset threshold, the selecting module selects at least one idle group that belongs to an MDS with a minimum load.

In combination with the third aspect or the several possible implementation manners of the third aspect, in a third possible implementation manner of the third aspect, the DDE further includes:

a group establishing module, configured to establish a preset number of idle groups before the acquiring module acquires the file fingerprint information of the file to be analyzed; and

a group allocation module, configured to allocate the preset number of idle groups to the multiple MDSs according to a preset allocation policy.

According to a fourth aspect, an embodiment of the present invention provides a meta data server MDS, including:

a receiving module, configured to receive an analysis request sent by a data de-duplicate engine DDE, where the analysis request carries file fingerprint information of a file to be analyzed;

an analysis module, configured to query each local file fingerprint information set, where each file fingerprint information set includes file fingerprint information in each group that the MDS is responsible for, and acquire a similarity between the file fingerprint information in the analysis request and each group that the MDS is responsible for; and

a sending module, configured to send an analysis result to the DDE, where the analysis result includes a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information.

In a first possible implementation manner of the fourth aspect, the analysis module is specifically configured to:

acquiring a similarity between file fingerprint information of each file in each group and the file fingerprint information in the analysis request; and

using, based on each group, the highest similarity among similarities between file fingerprint information of each file in a group and the file fingerprint information in the analysis request as a similarity between the group and the file fingerprint information in the analysis request, so as to obtain the similarity between each group and the file fingerprint information in the analysis request.

In combination with the fourth aspect or the first possible implementation manner of the fourth aspect, in a second possible implementation manner of the fourth aspect, the receiving module is further configured to receive a querying request of the DDE, where the querying request includes block fingerprint information of each data block in the file to be analyzed and a group number of a group selected by the DDE; and

the MDS further includes:

a querying module, configured to compare the block fingerprint information of each data block with a block fingerprint information base in the selected group, so as to query a duplicate data block, where the block fingerprint information base in the selected group includes block fingerprint information in the selected group; and

a saving module, configured to save block fingerprint information of a non-duplicate data block among each data block to the block fingerprint information base in the selected group; and save the file fingerprint information of the file to be analyzed to a file fingerprint information set in the selected group.

According to a fifth aspect, an embodiment of the present invention provides a similarity analysis system, including:

the DDE and multiple MDSs described above.

At least one technical solution among the multiple technical solutions brings the following advantage or beneficial effect:

In this embodiment of the present invention, the following technical means are adopted: Send an analysis request that carries file fingerprint information to at least two MDSs (Meta Data Server, MDS for short), so that the at least two MDSs query their respective local file fingerprint information sets, a local file fingerprint information set of each group that each MDS is responsible for; select at least one group according to an analysis result that is returned by each MDS and carries a found group number and a similarity of at least one group that has the highest similarity with the file fingerprint information; and send block fingerprint information of each data block in the file to be analyzed to an MDS that the selected group belongs to, so that the MDS queries a duplicate data block. In this way, each MDS needs to query only a file fingerprint information set of a group that the MDS itself is responsible for, which reduces the amount of data retrieval and waiting time of reading, writing, and locking a database file. Further, multiple MDSs concurrently complete a similarity analysis, thereby improving performance of the similarity analysis. In addition, in this embodiment of the present invention, an MDS completes a large number of calculation and sorting work in the similarity analysis, thereby reducing occupied resources of a DDE.

BRIEF DESCRIPTION OF DRAWINGS

To illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings required for describing the embodiments . Apparently, the accompanying drawings in the following description show merely some embodiments of the present invention, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

FIG. 1 is a schematic flowchart of a similarity analysis method according to an embodiment of the present invention;

FIG. 2 is a schematic flowchart of another similarity analysis method according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a DDE300 according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an MDS400 according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of another DDE500 according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of another MDS600 according to an embodiment of the present invention; and

FIG. 7 is a schematic structural diagram of a similarity analysis system 700 according to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

To make the objectives, technical solutions, and advantages of the embodiments of the present invention more comprehensible, the following clearly describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely a part rather than all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

FIG. 1 is a schematic flowchart of a similarity analysis method according to an embodiment of the present invention. As shown in FIG. 1, the method includes:

101. Acquire file fingerprint information of a file to be analyzed.

For example, a data de-duplicate engine (Data De-duplicate Engine, DDE for short) provided in an embodiment of the present invention acquires the file fingerprint information of the file to be analyzed. The file to be analyzed may be any file to be stored.

101 may include:

dividing the file to be analyzed into at least one data block;

extracting block fingerprint information of at least one data block from a data block obtained after the file to be analyzed is processed; and

combining the block fingerprint information of the at least one data block into the file fingerprint information of the file to be analyzed.

Block fingerprint information of a data block is included in meta data of the data block. The method of combining the block fingerprint information of the at least one data block into the file fingerprint information of the file to be analyzed is specifically as follows: combining block fingerprint information of all of or part of data blocks of the file to be analyzed into the file fingerprint information of the file to be analyzed.

102. Send an analysis request that carries the file fingerprint information to at least two MDSs, so that the at least two MDSs query their respective local file fingerprint information sets according to the file fingerprint information, where each file fingerprint information set includes file fingerprint information in each group that the MDSs are responsible for.

Specifically, the multiple MDSs may be located on different nodes in a storage system. Generally, one MDS and one DDE are set on each node in the storage system. Each group includes a file fingerprint information set and a block fingerprint information base of the group, and each group has a unique group number. A file fingerprint information set of a group includes all file fingerprint information of the group, and a block fingerprint information base of a group includes all block fingerprint information of the group. Alternatively, a group that each MDS is responsible for is determined when a group is pre-established. One MDS may be responsible for one or more groups. If m groups are pre-established and there are n MDSs in total, each MDS is responsible for maintaining m/n groups according to an average allocation policy, that is, each MDS is responsible for file fingerprint information sets and block fingerprint information bases of m/n groups. Specifically, both a file fingerprint information set and a block fingerprint information base are stored in the form of a database file.

The file fingerprint information set of each group includes at least one piece of file fingerprint information. Each MDS traverses each piece of file fingerprint information in a file fingerprint information set of a group that each MDS is responsible for, calculates a similarity between the file fingerprint information in the analysis request and each piece of file fingerprint information in the file fingerprint information set of the group that each MDS is responsible for. For example, the file fingerprint information in the analysis request is (A, B, C), and file fingerprint information in a file fingerprint information set is (A, C, D, E). In this case, a similarity of the two is the number of pieces of same block fingerprint information of the two divided by the total number of pieces of block fingerprint information of the two, that is, ⅖=0.4. The foregoing is only an example of a method for calculating a similarity, and this embodiment does not limit a method for calculating a similarity.

103. Select at least one group according to an analysis result returned by each MDS, where the analysis result includes a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information and is found by each MDS according to each local file fingerprint information set.

A group that has the highest similarity may be selected. Accordingly, 103 may include: selecting at least one group that has the highest similarity in the analysis result returned by each MDS.

Alternatively, the selecting at least one group according to an analysis result returned by each MDS may include: determining whether the at least one group that has the highest similarity in the analysis result returned by the MDS complies with a preset group selection policy, where the group selection policy generally refers to a similarity threshold. Accordingly, 103 may include: if at least one highest similarity in the analysis result returned by each MDS is higher than a preset threshold, selecting at least one group corresponding to the at least one highest similarity.

At least one pre-established idle group is selected if no similarity in the analysis result returned by each MDS is higher than the preset threshold. Further, for the purpose of achieving load balance, an idle group that belongs to an MDS with a relatively low load may be selected during idle group selection. Accordingly, the analysis result further includes load information of each MDS; and the selecting at least one pre-established idle group includes: selecting at least one idle group that belongs to an MDS with a minimum load.

Specifically, the load information of each MDS includes the number of files that the MDS is querying for a duplicate data block.

Further, before 101, the method further includes:

establishing a preset number of idle groups; and

allocating the preset number of idle groups to the multiple MDSs according to a preset allocation policy.

Specifically, during initialization, according to the quantity in a configuration file and an allocation policy, a corresponding number of idle groups are established and all the established idle groups are allocated to the multiple MDSs. For example, the allocation policy may be random allocation or average allocation. Each MDS is responsible for maintaining a group allocated to itself, and an MDS may be responsible for one or more groups. Generally, establishing an idle group refers to that a group number and storage space are allocated for the group and a file fingerprint information set and a block fingerprint information base of the idle group are empty.

104. Send block fingerprint information of each data block in the file to be analyzed to an MDS that the selected group belongs to, so that the MDS compares the block fingerprint information of each data block in the file to be analyzed with a local block fingerprint information base in the selected group, so as to query a duplicate data block, where the block fingerprint information base in the selected group includes block fingerprint information.

Specifically, if one group is selected, the block fingerprint information of each data block in the file to be analyzed is sent to the MDS that the selected group belongs to; if multiple groups are selected, the block fingerprint information of each data block in the file to be analyzed is sent to an MDS that each of the selected groups belongs to, where each of the selected groups is preferentially belongs to the same MDS, and this is not limited in this embodiment.

Specifically, the MDS that the selected group belongs to queries whether the block fingerprint information base of the selected group has block fingerprint information that is the same as the block fingerprint information of the data block in the file to be analyzed. If yes, it indicates that a block the same as the data block exists. If no, it indicates that no block the same as the data block exists, and then the block fingerprint information of the data block is added into the block fingerprint information base of the selected group. Afterwards, the MDS that the selected group belongs to saves the file fingerprint information of the file, to be analyzed to a file fingerprint information set in the selected group. It should be noted that, because a block fingerprint information base of an idle group is empty, if an idle group is selected in 103, the MDS cannot find block fingerprint information the same as the block fingerprint information of each data block in the file to be analyzed. Accordingly, the MDS stores the block fingerprint information of each data block in the file to be analyzed into the block fingerprint information base of the idle group, and saves the file fingerprint information of the file to be analyzed into the file fingerprint information set of the idle group. Then, the idle group is not idle any more.

In 102, alternatively, the DDE directly broadcasts the analysis request that carries the file fingerprint information to all MDSs. Alternatively, the DDE first matches the file fingerprint information of the file to be analyzed with pre-stored characteristic information of each group, determines a group matching the file to be analyzed, and then sends the analysis request to the MDS that the matched group belongs to. Specifically, characteristic information of each group may be obtained according to a file fingerprint information set of each group. It should be noted that, in this scenario, matching workload of the DDE is less than the workload for the MDS to calculate a similarity between file fingerprint information in an analysis request and each group.

In this embodiment of the present invention, the following technical means are adopted: Send an analysis request that carries file fingerprint information to at least two MDSs, so that the at least two MDSs query, according to the file fingerprint information, their respective local file fingerprint information sets of each group that each MDS is responsible for; select at least one group according to an analysis result that is returned by each MDS and carries a found group number and a similarity of at least one group that has the highest similarity with the file fingerprint information; and send block fingerprint information of each data block in the file to be analyzed to the MDS that the selected group belongs to, so that the MDS queries a duplicate data block. In this way, each MDS needs to query only a file fingerprint information set of a group that the MDS itself is responsible for, which reduces the amount of data retrieval and waiting time of reading, writing, and locking a database file. Further, multiple MDSs concurrently complete a similarity analysis, thereby improving the performance of the similarity analysis. In addition, in this embodiment of the present invention, an MDS completes a large number of calculation and sorting work in the similarity analysis, thereby reducing occupied resources of a DDE.

FIG. 2 is a schematic flowchart of another similarity analysis method according to an embodiment of the present invention. As shown in FIG. 2, the method includes:

201. Receive an analysis request sent by a DDE, where the analysis request carries file fingerprint information of a file to be analyzed.

For example, each MDS provided in an embodiment of the present invention separately receives the analysis request sent by the DDE. The file to be analyzed may be any file to be stored. Specifically, the DDE is located on one node in a storage system. Generally, one MDS and one DDE are set on each node in the storage system.

202. Query each local file fingerprint information set, where each file fingerprint information set includes file fingerprint information in each group that an MDS is responsible for, and acquire a similarity between the file fingerprint information in the analysis request and each group that the MDS is responsible for.

Specifically, each group includes a file fingerprint information set and a block fingerprint information base of the group, and each group has a unique group number. Alternatively, a group that each MDS is responsible for is determined when a group is pre-established. One MDS may be responsible for one or more groups. For example, if m groups are pre-established and there are n MDSs in total, each MDS is responsible for maintaining m/n groups according to an average allocation policy, that is, each MDS is responsible for file fingerprint information sets and block fingerprint information bases of m/n groups. Specifically, both a file fingerprint information set and a block fingerprint information base are stored in the form of a database file.

The file fingerprint information set of each group includes at least one piece of file fingerprint information. Each MDS traverses each piece of file fingerprint information in a file fingerprint information set of a group that each MDS is responsible for, calculates a similarity between the file fingerprint information in the analysis request and each piece of file fingerprint information in the file fingerprint information set of the group that each MDS is responsible for. For example, the file fingerprint information in the analysis request is (A, B, C), and file fingerprint information in a file fingerprint information set is (A, C, D, E). In this case, a similarity of the two is the number of pieces of same block fingerprint information of the two divided by the total number of pieces of block fingerprint information of the two, that is, ⅖=0.4.

Specifically, 202 may include:

acquiring a similarity between file fingerprint information of each file in each group and the file fingerprint information in the analysis request; and

using, based on each group, the highest similarity among similarities between file fingerprint information of each file in a group and the file fingerprint information in the analysis request as a similarity between the group and the file fingerprint information in the analysis request, so as to obtain the similarity between each group and the file fingerprint information in the analysis request.

For example, the file fingerprint information in the analysis request is X, and a file fingerprint information set in group A includes file fingerprint information a, b, and c. If a similarity between X and a is 0.5, a similarity between X and b is 0.7, and a similarity between X and c is 0.45, a similarity between X and group A is 0.7.

203. Send an analysis result to the DDE, where the analysis result includes a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information.

For example, an MDS is responsible for group A, group B, and group C. A similarity between the file fingerprint information X in the analysis request and group A is 0.7, a similarity between the file fingerprint information X in the analysis request and group B is 0.6, and a similarity between the file fingerprint information X in the analysis request and group C is 0.5. If the analysis result includes a group number and a similarity of only one group with the highest similarity, the analysis result includes the similarity 0.7 and the group number of group A, which may be alternatively expressed by a 2-tuple (A, 0.7). If the analysis result includes group numbers and similarities of two groups with the highest similarity, the analysis result includes the similarity 0.7 and the group number of group A, and the similarity 0.6 and the group number of group B, which may be alternatively expressed by (A, 0.7) and (B, 0.6). Generally, the number of groups with the highest similarity and whose group numbers and similarities are included in the analysis result may be preset and may also be specified by the DDE in the analysis request.

Further, if the DDE selects a group that the MDS is responsible for to query a duplicate data block, after 203, the method may further include:

receiving a querying request of the DDE, where the querying request includes block fingerprint information of each data block in the file to be analyzed and a group number of a group selected by the DDE;

comparing the block fingerprint information of each data block with a block fingerprint information base in the selected group, so as to query a duplicate data block, where the block fingerprint information base in the selected group includes block fingerprint information;

saving block fingerprint information of a non-duplicate data block among each data block to the block fingerprint information base in the selected group; and

saving the file fingerprint information of the file to be analyzed to a file fingerprint information set in the selected group.

Generally, the DDE selects at least one group to query a duplicate data block. Specifically, if one group is selected, the block fingerprint information of each data block in the file to be analyzed is sent to the MDS that the selected group belongs to; if multiple groups are selected, the block fingerprint information of each data block in the file to be analyzed is sent to an MDS that each of the selected groups belongs to, where each of the selected groups is preferentially belongs to the same MDS, and this is not limited in this embodiment.

If an MDS receives a querying request of a DDE, it indicates that the DDE selects a group that the MDS is responsible for to query a duplicate data block, if the querying request of the DDE includes only a group number of one group of the MDS in addition to block fingerprint information of each data block, the MDS queries a duplicate data block only in the group. If the querying request of the DDE includes only group numbers of multiple groups of the MDS in addition to block fingerprint information of each data block, the MDS queries a duplicate data block only in the multiple groups. Specifically, a data block is a non-duplicate data block only when no block fingerprint information the same as block fingerprint information of the data block is found in block fingerprint information bases of the multiple groups. The block fingerprint information of the non-duplicate data block is saved into the block fingerprint information base of a group among the multiple groups. Accordingly, the file fingerprint information of the file to be analyzed is saved into the file fingerprint information set of the group.

In this embodiment of the present invention, the following technical means are adopted: Receive an analysis request that is sent by a DDE and carries file fingerprint information, query a file fingerprint information set of each group that an MDS is responsible for, acquire a similarity between the file fingerprint information and each group that the MDS is responsible for, and send an analysis result including a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information to the DDE, so that the DDE selects at least one group to query a duplicate data block. In this way, each MDS needs to query only a file fingerprint information set of a group that the MDS itself is responsible for, which reduces the amount of data retrieval and waiting time of reading, writing, and locking a database file. Further, multiple MDSs concurrently complete a similarity analysis, thereby improving performance of the similarity analysis. In addition, in this embodiment of the present invention, an MDS completes a large number of calculation and sorting work in the similarity analysis, thereby reducing occupied resources of a DDE.

Persons of ordinary skill in the art may understand that all or a part of the steps in each of the foregoing method embodiments may be implemented by a program instructing relevant hardware. The program may be stored in a computer readable storage medium. When the program is run, the steps in the method embodiments are performed. The storage medium may be any medium that is capable of storing program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

FIG. 3 is a schematic structural diagram of a DDE300 according to an embodiment of the present invention. As shown in FIG. 3, the DDE300 includes:

an acquiring module 31, configured to acquire file fingerprint information of a file to be analyzed;

a sending module 32, configured to send an analysis request that carries the file fingerprint information to at least two servers (MDSs) meta data servers (MDSs), so that the at least two MDSs query their respective local file fingerprint information sets according to the file fingerprint information, where each file fingerprint information set includes file fingerprint information in each group that the MDSs are responsible for;

a selecting module 33, configured to select at least one group according to an analysis result returned by each MDS, where the analysis result includes a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information and is found by each MDS according to each local file fingerprint information set; and

an allocation module 34, configured to send block fingerprint information, acquired in advance, of each data block in the file to be analyzed to an MDS that the selected group belongs to, so that the MDS compares the block fingerprint information of each data block in the file to be analyzed with a local block fingerprint information base in the selected group, so as to query a duplicate data block, where the block fingerprint information base in the selected group includes block fingerprint information.

In this embodiment, the DDE300 and each MDS may be located on a same node or different nodes in a storage system. Generally, one MDS and one DDE are set on each node.

Further, the selecting module 33 is specifically configured to:

select at least one group with the highest similarity in an analysis result returned by each MDS.

Alternatively, the selecting module 33 is specifically configured to:

if at least one highest similarity in the analysis result returned by each MDS is higher than a preset threshold, select at least one group corresponding to the at least one highest similarity.

Further, the selecting module 33 is specifically configured to:

select at least one pre-established idle group if no similarity in the analysis result returned by each MDS is higher than the preset threshold.

Preferentially, the analysis result further includes load information of each MDS; and in the condition that no similarity in the analysis result returned by each MDS is higher than the preset threshold, the selecting module 33 selects at least one idle group that belongs to an MDS with a minimum load.

Specifically, the load information of each MDS includes the number of files that the MDS is querying for a duplicate data block.

Further, the DDE300 further includes:

a group establishing module, configured to establish a preset number of idle groups before the acquiring module 31 acquires the file fingerprint information of the file to be analyzed;

and a group allocation module, configured to allocate the preset number of idle groups to the multiple MDSs according to a preset allocation policy.

Further, the acquiring module 31 includes:

a block dividing unit, configured to divide the file to be analyzed into at least one data block;

an extraction unit, configured to extract block fingerprint information of at least one data block from a data block obtained after the file is processed;

a generation unit, configured to combine the block fingerprint information of the at least one data block into the file fingerprint information of the file to be analyzed.

For specific implementation of this embodiment, refer to a similarity analysis method provided in the embodiment of the present invention. In this embodiment of the present invention, the following technical means are adopted: A DDE sends an analysis request that carries file fingerprint information to at least two MDSs, so that the at least two MDSs separately query, according to the file fingerprint information, their respective local file fingerprint information sets of each group that each MDS is responsible for; selects at least one group according to an analysis result that is returned by each MDS and carries a found group number and a similarity of at least one group that has the highest similarity with the file fingerprint information; and sends block fingerprint information of each data block in the file to be analyzed to the MDS that the selected group belongs to, so that the MDS queries a duplicate data block. In this way, each MDS needs to query only a file fingerprint information set of a group that the MDS itself is responsible for, which reduces the amount of data retrieval and waiting time of reading, writing, and locking a database file. Further, multiple MDSs concurrently complete a similarity analysis, thereby improving performance of the similarity analysis. In addition, in this embodiment of the present invention, an MDS completes a large number of calculation and sorting work in the similarity analysis, thereby reducing occupied resources of a DDE.

FIG. 4 is a schematic structural diagram of an MDS400 according to an embodiment of the present invention. As shown in FIG. 4, the MDS400 includes:

a receiving module 41, configured to receive an analysis request sent by a DDE, where the analysis request carries file fingerprint information of a file to be analyzed;

an analysis module 42, configured to query each local file fingerprint information set, where each file fingerprint information set includes file fingerprint information in each group that the MDS is responsible for, and acquire a similarity between the file fingerprint information in the analysis request and each group that the MDS is responsible for; and

a sending module 43, configured to send an analysis result to the DDE, where the analysis result includes a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information.

Further, the analysis module 42 is specifically configured to:

acquire a similarity between file fingerprint information of each file in each group and the file fingerprint information in the analysis request; and

use, based on each group, the highest similarity among similarities between file fingerprint information of each file in a group and the file fingerprint information in the analysis request as a similarity between the group and the file fingerprint information in the analysis request, so as to obtain the similarity between each group and the file fingerprint information in the analysis request.

Further, the analysis module 41 is further configured to: receive a querying request of the DDE, where the querying request includes block fingerprint information of each data block in the file to be analyzed and a group number of a group selected by the DDE.

The MDS400 further includes:

a querying module, configured to compare the block fingerprint information of each data block with a block fingerprint information base in the selected group, so as to query a duplicate data block, where the block fingerprint information base in the selected group includes block fingerprint information in the selected group; and

a saving module, configured to save block fingerprint information of a non-duplicate data block among each data block to the block fingerprint information base in the selected group; and save the file fingerprint information of the file to be analyzed to a file fingerprint information set in the selected group.

For specific implementation of this embodiment, refer to another similarity analysis method provided in the embodiment of the present invention. In this embodiment of the present invention, the following technical means are adopted: An MDS receives an analysis request that is sent by a DDE and carries file fingerprint information, queries a local file fingerprint information set in each group that the MDS is responsible for, acquires a similarity between the file fingerprint information and each group that the MDS is responsible for, and sends an analysis result including a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information to the DDE, so that the DDE selects at least one group to query a duplicate data block. In this way, each MDS needs to query only a file fingerprint information set of a group that the MDS itself is responsible for, which reduces the amount of data retrieval and waiting time of reading, writing, and locking a database file. Further, multiple MDSs concurrently complete a similarity analysis, thereby improving performance of the similarity analysis. In addition, in this embodiment of the present invention, an MDS completes a large number of calculation and sorting work in the similarity analysis, thereby reducing occupied resources of a DDE.

FIG. 5 is a schematic structural diagram of another DDE500 according to an embodiment of the present invention. As shown in FIG. 5, the DDE500 generally includes at least one processor 510, for example, a central processing unit (Central Processing Unit, CPU for short), a digital signal processor (Digital Signal Processor, DSP for short), at least one port 520, a memory 530, and at least one communication bus 540. The communication bus 540 is configured to implement connection communication among the apparatuses. The processor 510 is configured to perform an executable module stored in the memory 530, for example, a computer program; alternatively, the DDE500 may include a user interface 550, and the user interface 550 includes but is not limited to a monitor, a keyboard, and a clicking device, for example, a mouse, a trackball (trackball), a touch panel, or a touchscreen. The memory 530 may include a high-speed random access memory (Random Access Memory, RAM for short), and may further include a non-volatile memory (non-volatile memory), for example, at least one disk memory.

In some implementation manners, the memory 530 stores the following elements: an executable module or a data structure, or their subsets, or their extension sets:

an operating system 532, including various system programs and configured to implement various basic services and process a hardware-based task; and

an application module 534, including various application programs and configured to implement various application services.

The application module 534 includes but is not limited to an acquiring module 31, a sending module 32, a selecting module 33, and an allocation module 34. Further, the application module 534 further includes: a group establishing module and a group allocation module.

For specific implementation of each module in the application module 534, refer to a corresponding module in the DDE300. No further details are provided herein.

In this embodiment of the present invention, the following technical means are adopted: A DDE sends an analysis request that carries file fingerprint information to at least two MDSs, so that the at least two MDSs query, according to the file fingerprint information, their respective local file fingerprint information sets of each group that each MDS is responsible for; selects at least one group according to an analysis result that is returned by each MDS and carries a found group number and a similarity of at least one group that has the highest similarity with the file fingerprint information; and sends block fingerprint information of each data block in the file to be analyzed to the MDS that the selected group belongs to, so that the MDS queries a duplicate data block. In this way, each MDS needs to query only a file fingerprint information set of a group that the MDS itself is responsible for, which reduces the amount of data retrieval and waiting time of reading, writing, and locking a database file. Further, multiple MDSs concurrently complete a similarity analysis, thereby improving performance of the similarity analysis. In addition, in this embodiment of the present invention, an MDS completes a large number of calculation and sorting work in the similarity analysis, thereby reducing occupied resources of a DDE.

FIG. 6 is a schematic structural diagram of another MDS600 according to an embodiment of the present invention.

The MDS600 generally includes at least one processor 610, for example, a CPU and a DSP, at least one port 620, a memory 630, and at least one communication bus 640.

The communication bus 640 is configured to implement connection communication among the apparatuses. The processor 610 is configured to perform an executable module stored in the memory 630, for example, a computer program; alternatively, the MDS600 may include a user interface 650, and the user interface 650 includes but is not limited to a monitor, a keyboard, and a clicking device, for example, a mouse, a trackball (trackball), a touch panel, or a touchscreen. The memory 630 may include a RAM, and may further include a non-volatile memory (non-volatile memory), for example, at least one disk memory.

In some implementation manners, the memory 630 stores the following elements, an executable module or a data structure, or their subsets, or their extension sets:

an operating system 632, including various system programs and configured to implement various basic services and process a hardware-based task; and

an application module 634, including various application programs and configured to implement various application services.

The application module 634 includes but is not limited to a receiving module 41, an analysis module 42, and a sending module 43. Further, the application module 634 further includes: a querying module and a saving module.

For specific implementation of each module in the application module 634, refer to a corresponding module in the MDS400. No further details are provided herein.

In this embodiment of the present invention, the following technical means are adopted: An MDS receives an analysis request that is sent by a DDE and carries file fingerprint information, queries a local file fingerprint information set in each group that the MDS is responsible for, acquires a similarity between the file fingerprint information and each group that the MDS is responsible for, and sends an analysis result including a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information to the DDE, so that the DDE selects at least one group to query a duplicate data block. In this way, each MDS needs to query only a file fingerprint information set of a group that the MDS itself is responsible for, which reduces the amount of data retrieval and waiting time of reading, writing, and locking a database file. Further, multiple MDSs concurrently complete a similarity analysis, thereby improving performance of the similarity analysis. In addition, in this embodiment of the present invention, an MDS completes a large number of calculation and sorting work in the similarity analysis, thereby reducing occupied resources of a DDE.

An embodiment of the present invention provides a computer program product, where the computer program product includes a computer readable storage medium for storing a program code, and the program code includes an instruction. The instruction is used to:

acquire file fingerprint information of a file to be analyzed;

send an analysis request that carries the file fingerprint information to at least two MDSs, so that the at least two MDSs query their respective local file fingerprint information sets according to the file fingerprint information, where each file fingerprint information set includes file fingerprint information in each group that the MDSs are responsible for;

select at least one group according to an analysis result returned by each MDS, where the analysis result includes a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information and is found by each MDS according to each local file fingerprint information set; and

send block fingerprint information, acquired in advance, of each data block in the file to be analyzed to an MDS that the selected group belongs to, so that the MDS compares the block fingerprint information of each data block in the file to be analyzed with a local block fingerprint information base in the selected group, so as to query a duplicate data block, where the block fingerprint information base in the selected group includes block fingerprint information.

Further, the instruction is specifically configured to:

if at least one highest similarity in the analysis result returned by each MDS is higher than a preset threshold, select at least one group corresponding to the at least one highest similarity; and

select at least one pre-established idle group if no similarity in the analysis result returned by each MDS is higher than the preset threshold.

Further, the analysis result further includes load information of each MDS; the instruction is specifically configured to, in the condition that no similarity in the analysis result returned by each MDS is higher than the preset threshold, select at least one idle group that belongs to an MDS with a minimum load.

Further, the instruction is further used to:

establish a preset number of idle groups; and

allocate the preset number of idle groups to the multiple MDSs according to a preset allocation policy.

In this embodiment of the present invention, the following technical means are adopted: A DDE sends an analysis request that carries file fingerprint information to at least two MDSs, so that the at least two MDSs query, according to the file fingerprint information, their respective local file fingerprint information sets of each group that each MDS is responsible for; selects at least one group according to an analysis result that is returned by each MDS and carries a found group number and a similarity of at least one group that has the highest similarity with the file fingerprint information; and sends block fingerprint information of each data block in the file to be analyzed to the MDS that the selected group belongs to, so that the MDS queries a duplicate data block. In this way, each MDS needs to query only a file fingerprint information set of a group that the MDS itself is responsible for, which reduces the amount of data retrieval and waiting time of reading, writing, and locking a database file. Further, multiple MDSs concurrently complete a similarity analysis, thereby improving performance of the similarity analysis. In addition, in this embodiment of the present invention, an MDS completes a large number of calculation and sorting work in the similarity analysis, thereby reducing occupied resources of a DDE.

An embodiment of the present invention provides another computer program product, where the computer program product includes a computer readable storage medium for storing a program code, and the program code includes an instruction. The instruction is used to:

receive an analysis request sent by a DDE, where the analysis request carries file fingerprint information of a file to be analyzed;

query each local file fingerprint information set, where each file fingerprint information set includes file fingerprint information in each group that an MDS is responsible for, and acquire a similarity between the file fingerprint information in the analysis request and each group that the MDS is responsible for; and

send an analysis result to the DDE, where the analysis result includes a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information.

Further, the instruction is specifically used to:

acquire a similarity between file fingerprint information of each file in each group and the file fingerprint information in the analysis request; and

use, based on each group, the highest similarity among similarities between file fingerprint information of each file in a group and the file fingerprint information in the analysis request as a similarity between the group and the file fingerprint information in the analysis request, so as to obtain the similarity between each group and the file fingerprint information in the analysis request.

Further, the instruction is further used to:

receive a querying request of the DDE, where the querying request includes block fingerprint information of each data block in the file to be analyzed and a group number of a group selected by the DDE;

compare the block fingerprint information of each data block with a block fingerprint information base in the selected group, so as to query a duplicate data block, where the block fingerprint information base in the selected group includes block fingerprint information;

save block fingerprint information of a non-duplicate data block among each data block to the block fingerprint information base in the selected group; and

save the file fingerprint information of the file to be analyzed to a file fingerprint information set in the selected group.

In this embodiment of the present invention, the following technical means are adopted: An MDS receives an analysis request that is sent by a DDE and carries file fingerprint information, queries a local file fingerprint information set in each group that the MDS is responsible for, acquires a similarity between the file fingerprint information and each group that the MDS is responsible for, and sends an analysis result including a group number and a similarity of at least one group that has the highest similarity with the file fingerprint information to the DDE, so that the DDE selects at least one group to query a duplicate data block. In this way, each MDS needs to query only a file fingerprint information set of a group that the MDS itself is responsible for, which reduces the amount of data retrieval and waiting time of reading, writing, and locking a database file. Further, multiple MDSs concurrently complete a similarity analysis, thereby improving performance of the similarity analysis. In addition, in this embodiment of the present invention, an MDS completes a large number of calculation and sorting work in the similarity analysis, thereby reducing occupied resources of a DDE.

FIG. 7 is a schematic structural diagram of a similarity analysis system 700 according to an embodiment of the present invention. As shown in FIG. 7, the system includes:

a DDE71 and multiple MDS72s, where:

the DDE71 is a DDE provided in an embodiment of the present invention, and each MDS72 is an MDS provided in an embodiment of the present invention.

Further, there are multiple DDE71s.

Each DDE71 and each MDS72 may be located on a same node or different nodes in a storage system. Generally, one MDS and one DDE are set on each node.

For specific implementation of this embodiment, refer to a DDE provided in an embodiment of the present invention and an MDS provided in an embodiment of the present invention. In this embodiment of the present invention, the following technical means are adopted: A DDE sends an analysis request that carries file fingerprint information to at least two MDSs, so that the at least two MDSs query, according to the file fingerprint information, their respective local file fingerprint information sets of each group that each MDS is responsible for; selects at least one group according to an analysis result that is returned by each MDS and carries a found group number and a similarity of at least one group that has the highest similarity with the file fingerprint information; and sends block fingerprint information of each data block in the file to be analyzed to the MDS that the selected group belongs to, so that the MDS queries a duplicate data block. In this way, each MDS needs to query only a file fingerprint information set of a group that the MDS itself is responsible for, which reduces the amount of data retrieval and waiting time of reading, writing, and locking a database file. Further, multiple MDSs concurrently complete a similarity analysis, thereby improving performance of the similarity analysis. In addition, in this embodiment of the present invention, an MDS completes a large number of calculation and sorting work in the similarity analysis, thereby reducing occupied resources of a DDE.

Finally, it should be noted that the foregoing embodiments are merely intended for describing the technical solutions of the present invention other than limiting the present invention. Although the present invention is described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that he may still make modifications to the technical solutions described in the foregoing embodiments, or make equivalent replacements to some technical features thereof, without departing from the scope of the technical solutions of the embodiments of the present invention. 

What is claimed is:
 1. A similarity analysis method, comprising following steps performed by a data de-duplicate apparatus: acquiring file fingerprint information of a file to be analyzed; sending an analysis request that carries the file fingerprint information to at least two meta data servers (MDSs), wherein the at least two MDSs are each assigned at least one fingerprint information group, and the at least two MDSs respectively query a local file fingerprint information set in their assigned fingerprint information group according to the file fingerprint information of the file to be analyzed; receiving an analysis result respectively returned by each of the at least two MDSs based on the query, wherein the analysis result comprises a group number of a fingerprint information group which has the highest similarity value with the file fingerprint information of the file to be analyzed among the assigned at least one fingerprint information group, and the similarity value; selecting at least one fingerprint information group according to the received analysis result; and sending block fingerprint information of each data block in the file to be analyzed to an MDS of the at least two MDSs that the selected fingerprint information group belongs to, wherein the MDS that the selected fingerprint information group belongs to compares the block fingerprint information of each data block in the file to be analyzed with local block fingerprint information in the selected fingerprint information group to query a duplicate data block.
 2. The method according to claim 1, wherein the selecting at least one fingerprint information group according to the received analysis result comprises: determining that at least one highest similarity value in the received analysis result is higher than a threshold; and based on the determination, selecting at least one fingerprint information group corresponding to the at least one highest similarity value.
 3. The method according to claim 1, wherein the selecting at least one fingerprint information group according to the received analysis result comprises: determining that no similarity value in the received analysis result is higher than a threshold; and based on the determination, selecting at least one idle group.
 4. The method according to claim 3, wherein before the acquiring the file fingerprint information of the file to be analyzed, the method further comprises: establishing a number of idle groups; and allocating the number of idle groups to the at least two MDSs according to a allocation policy.
 5. The method according to claim 4, wherein the analysis result further comprises load information of each MDS; and wherein the selecting at least one idle group comprises: selecting at least one idle group that belongs to an MDS with a minimum load according to the load information.
 6. A similarity analysis method, comprising following steps performed by a meta data server (MDS): receiving an analysis request sent by a data de-duplicate engine (DDE), wherein the analysis request carries file fingerprint information of a file to be analyzed; respectively acquiring a similarity value between the file fingerprint information of the file to be analyzed and each of at least one assigned fingerprint information group through querying a local file fingerprint information set in each of the at least one assigned fingerprint information group according to the file fingerprint information of the file to be analyzed ; and sending an analysis result to the DDE, wherein the analysis result comprises a group number of a fingerprint information group which has the highest similarity value with the file fingerprint information of the file to be analyzed among the assigned at least one fingerprint information group, and the similarity value.
 7. The method according to claim 6, wherein the acquiring the similarity value between the file fingerprint information of the file to be analyzed and one of the at least one assigned fingerprint information group comprises: acquiring similarity values between the file fingerprint information of the file to be analyzed and each of multiple pieces of file fingerprint information in the local file fingerprint information set in the one of the at least one assigned fingerprint information group ; and determining a highest similarity value among the acquired similarity values as the similarity value between the file fingerprint information of the file to be analyzed and the one of the at least one assigned fingerprint information group.
 8. The method according to claim 6, wherein after the sending the analysis result to the DDE, the method further comprises: receiving a querying request of the DDE, wherein the querying request comprises block fingerprint information of each data block in the file to be analyzed and a group number of a fingerprint information group in the at least one assigned fingerprint information group selected by the DDE; comparing the block fingerprint information of each data block in the file to be analyzed with block fingerprint information in the selected fingerprint information group to query a duplicate data block.
 9. The method according to claim 8, wherein the method further comprises: determining a non-duplicate data block among data blocks in the file to be analyzed based on the comparing; based on the determination, saving block fingerprint information of the non-duplicate data block into the selected fingerprint information group, and saving the file fingerprint information of the file to be analyzed into the selected fingerprint information group.
 10. A similarity analysis system, comprising: a data de-duplicate engine (DDE) in communication with at least two metadata servers (MDSs); wherein the DDE is configured to acquire file fingerprint information of a file to be analyzed; send an analysis request that carries the file fingerprint information to the at least two MDSs, wherein the at least two MDSs are each assigned at least one fingerprint information group, and the at least two MDSs respectively query a local file fingerprint information set in their assigned fingerprint information group according to the file fingerprint information of the file to be analyzed; receive an analysis result respectively returned by each of the at least two MDSs based on the query, wherein the analysis result comprises a group number of a fingerprint information group which has the highest similarity value with the file fingerprint information of the file to be analyzed among the assigned at least one fingerprint information group, and the similarity value; select at least one fingerprint information group according to the received analysis result; and send block fingerprint information of each data block in the file to be analyzed to an MDS of the at least two MDSs that fingerprint information group belongs to, wherein the MDS that the selected fingerprint information group belongs to compares the block fingerprint information of each data block in the file to be analyzed with local block fingerprint information in the selected fingerprint information group to query a duplicate data block.
 11. The system according to claim 10, wherein the DDE being configured to select at least one fingerprint information group according to the received analysis result comprises: the DDE being configured to determine that at least one highest similarity value in the received analysis result is higher than a threshold; and based on the determination, select at least one fingerprint information group corresponding to the at least one highest similarity value.
 12. The system according to claims 10, wherein the DDE is further configured to establish a number of idle groups, and allocate the number of idle groups to the at least two MDSs according to a allocation policy.
 13. The system according to claim 12, wherein the analysis result further comprises load information of each MDS; and wherein the DDE being configured to select at least one fingerprint information group according to the received analysis result comprises: the DDE being configured to determine that no similarity value in the received analysis result is higher than a threshold, and based on the determination, select at least one idle group from the established number of idle groups.
 14. The system according to claim 10, further comprising the at least two MDSs, wherein the MDS is configured to receive an analysis request sent by a data de-duplicate engine (DDE), wherein the analysis request carries file fingerprint information of a file to be analyzed; respectively acquire a similarity value between the file fingerprint information of the file to be analyzed and each of at least one assigned fingerprint information group through querying a local file fingerprint information set in each of the at least one assigned fingerprint information group according to the file fingerprint information of the file to be analyzed ; and send an analysis result to the DDE, wherein the analysis result comprises a group number of a fingerprint information group which has the highest similarity value with the file fingerprint information of the file to be analyzed among the assigned at least one fingerprint information group, and the similarity value.
 15. The system according to claim 14, wherein the MDS being configured to acquire the similarity value between the file fingerprint information of the file to be analyzed and one of the at least one assigned fingerprint information group comprises: The MDS being configured to acquire similarity values between the file fingerprint information of the file to be analyzed and each of multiple pieces of file fingerprint information in the local file fingerprint information set in the one of the at least one assigned fingerprint information group ; and determine a highest similarity value among the acquired similarity values as the similarity value between the file fingerprint information of the file to be analyzed and the one of the at least one assigned fingerprint information group.
 16. The system according to claim 14, wherein after the send the analysis result to the DDE, the MDS further configured to receive a querying request of the DDE, wherein the querying request comprises block fingerprint information of each data block in the file to be analyzed and a group number of a fingerprint information group in the at least one assigned fingerprint information group selected by the DDE; and compare the block fingerprint information of each data block in the file to be analyzed with block fingerprint information in the selected fingerprint information group to query a duplicate data block.
 17. The system according to claim 16, wherein the MDS further configured to: determining a non-duplicate data block among data blocks in the file to be analyzed based on the comparing; based on the determination, saving block fingerprint information of the non-duplicate data block into the selected fingerprint information group, and saving the file fingerprint information of the file to be analyzed into the selected fingerprint information group. 